How to Change the Oil in a 1987 Suzuki DR100 – A Complete MotoSport.com Guide
Shop parts for a 1987 Suzuki DR100 Dirt Bike.
When it comes to maintaining your classic 1987 Suzuki DR100, a routine oil change is essential to keep your dirt bike running smoothly and extend its life. This DIY guide, proprietary to MotoSport.com, walks you through the oil change process for this specific model, including the tools you'll need, model-specific call-outs, and every step required for a successful job.
Tools & Supplies Needed
- Socket wrench set (including 17 mm and 10 mm sizes)
- Drain pan
- Funnel
- Gloves (for protection)
- Shop rags or paper towels
- Fresh oil: High-quality 4-stroke motorcycle oil, SAE 10W-40 recommended, about 1 quart (0.95L for the DR100)
- New oil filter (if applicable for your DR100's variant; consult service manual if unsure)
- Replacement crush washer for drain plug (recommended, optional)
- Screwdriver (if oil filter cover uses screws)
Step-by-Step Instructions
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Warm up the Engine
- Start the bike and let it idle for 2-3 minutes. This thins the oil, helping contaminants suspend for a cleaner drain.
- Safety Note: Make sure the bike is on a stand and stable before proceeding.
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Remove the Oil Filler Cap
- Unscrew the oil filler cap to allow air into the system. This helps the oil drain more freely.
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Locate the Oil Drain Bolt
- On the 1987 Suzuki DR100, find the drain bolt on the underside of the engine's left side.
- Use your 17 mm socket wrench to loosen (counterclockwise) and remove the drain bolt.
- Be careful—the oil may be hot. Allow all oil to drain into your pan.
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Remove and Replace the Oil Filter (if equipped)
- Not all DR100 variants have an external oil filter. For those that do, it will be housed behind a metal cover, secured by bolts or screws (typically 10 mm or Phillips head).
- Carefully remove the cover and old filter. Inspect the filter and sealing surfaces for debris or damage.
- Install the new filter, ensuring it sits correctly, and reattach the cover evenly. Tighten bolts to the specified torque – do not overtighten.
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Inspect and Replace Crush Washer
- Check the crush washer on your drain plug for wear. Replace if it's deformed or damaged to prevent leaks.
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Reinstall the Drain Plug
- Carefully thread the drain plug back into place by hand to prevent cross-threading, then tighten snugly with the wrench.
- Model Note: The 1987 DR100's small capacity—do not overtighten the drain bolt; 1/8 turn past snug is usually sufficient for this model.
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Add New Oil
- Check your manual for the exact capacity; approximately 1 quart (0.95L) of 10W-40 motorcycle oil is standard for the DR100.
- Insert a funnel in the filler hole and pour in oil slowly to avoid spills.
- Reinstall the filler cap and clean any drips.
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Check Oil Level
- Start the engine and let it idle for 1-2 minutes. Shut it off and wait another 2 minutes for oil to settle.
- With the bike level, remove the dipstick or filler cap and check the oil level. Add more if needed to reach the full mark.
- Do not overfill. Excess oil can cause engine damage.
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Check for Leaks
- With the engine off, inspect the drain plug and oil filter area for seepage.
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Dispose of Used Oil Properly
- Take drained oil and the old filter to a certified recycling center. Do not pour oil down the drain or onto the ground.
Special DR100 Model-Specific Callouts
- Oil Capacity: The 1987 DR100 uses approximately 1 quart (0.95 liters) of oil. Overfilling can cause pressure issues—always double-check the level against the “full” mark after fresh oil settles.
- Integrated Engine & Transmission Oil: Like many small Suzuki engines, both the crankcase and transmission share the oil. This makes proper oil changes even more critical.
- No External Oil Filter on Most Units: Unlike some larger Suzuki models, the '87 DR100 usually relies on a centrifugal filter or strainer inside the engine, not a replaceable external paper cartridge. If your DR100 has an external filter housing, replace the filter every oil change and use manufacturer-specified filters for best results. Consult the factory manual for locating and accessing the internal strainer, which should be cleaned periodically.
- Drain Plug Torque: Due to the small aluminum case, overtightening the drain bolt is a common cause of stripped threads. Hand-tighten first, then use a torque wrench if available—check your service manual for the exact spec.
Final Safety & Maintenance Tips
- Inspect oil for metal shavings or unusual debris—these may indicate engine wear.
- Check your air filter and perform a general safety inspection during each oil change for best performance.
- Always refer to the detailed diagrams and torque specs in the factory service manual for your DR100 when in doubt (1983-1990 Suzuki DR100 models are covered by the same manual).
- Stay consistent with oil changes. For typical use, change the oil every 1000-1500 miles or every 6 months, whichever comes first.
MotoSport.com is dedicated to providing proprietary, practical guides so you can keep your 1987 Suzuki DR100 running like new with confidence.
Related Shopping Categories
Shop Motor Oil for a 1987 Suzuki DR100 Dirt Bike.
Shop Oil Filters for a 1987 Suzuki DR100 Dirt Bike.
Shop Oil Drain Pans for a 1987 Suzuki DR100 Dirt Bike.
Shop Tools for a 1987 Suzuki DR100 Dirt Bike.
Shop Oil Fillers and Drain Plugs for a 1987 Suzuki DR100 Dirt Bike.
Disclaimer: This guide is provided for general informational purposes only and is not intended to replace your motorcycle's official owner's manual. Always refer to your manufacturer's documentation for model-specific instructions, torque specifications, safety procedures, and maintenance requirements. If you are unsure or inexperienced, consider seeking assistance from a qualified mechanic or technician.